Adds stand alone _md5 and _sha1 modules for use by hashlib on systems
when the OpenSSL library is either not present or not found by setup.py.

These are derived from the public domain libtomcrypt (libtom.org) just like
the existing sha256 and sha512 modules.
diff --git a/Modules/md5module.c b/Modules/md5module.c
new file mode 100644
index 0000000..26f0e4c
--- /dev/null
+++ b/Modules/md5module.c
@@ -0,0 +1,561 @@
+/* MD5 module */
+
+/* This module provides an interface to the MD5 algorithm */
+
+/* See below for information about the original code this module was
+   based upon. Additional work performed by:
+
+   Andrew Kuchling (amk@amk.ca)
+   Greg Stein (gstein@lyra.org)
+   Trevor Perrin (trevp@trevp.net)
+
+   Copyright (C) 2005-2007   Gregory P. Smith (greg@krypto.org)
+   Licensed to PSF under a Contributor Agreement.
+
+*/
+
+/* MD5 objects */
+
+#include "Python.h"
+
+
+/* Some useful types */
+
+#if SIZEOF_INT == 4
+typedef unsigned int MD5_INT32;	/* 32-bit integer */
+typedef PY_LONG_LONG MD5_INT64;	/* 64-bit integer */
+#else
+/* not defined. compilation will die. */
+#endif
+
+/* The MD5 block size and message digest sizes, in bytes */
+
+#define MD5_BLOCKSIZE    64
+#define MD5_DIGESTSIZE   16
+
+/* The structure for storing MD5 info */
+
+struct md5_state {
+    MD5_INT64 length;
+    MD5_INT32 state[4], curlen;
+    unsigned char buf[MD5_BLOCKSIZE];
+};
+
+typedef struct {
+    PyObject_HEAD
+
+    struct md5_state hash_state;
+} MD5object;
+
+
+/* ------------------------------------------------------------------------
+ *
+ * This code for the MD5 algorithm was noted as public domain. The
+ * original headers are pasted below.
+ *
+ * Several changes have been made to make it more compatible with the
+ * Python environment and desired interface.
+ *
+ */
+
+/* LibTomCrypt, modular cryptographic library -- Tom St Denis
+ *
+ * LibTomCrypt is a library that provides various cryptographic
+ * algorithms in a highly modular and flexible manner.
+ *
+ * The library is free for all purposes without any express
+ * guarantee it works.
+ *
+ * Tom St Denis, tomstdenis@gmail.com, http://libtom.org
+ */
+
+/* rotate the hard way (platform optimizations could be done) */
+#define ROLc(x, y) ( (((unsigned long)(x)<<(unsigned long)((y)&31)) | (((unsigned long)(x)&0xFFFFFFFFUL)>>(unsigned long)(32-((y)&31)))) & 0xFFFFFFFFUL)
+
+/* Endian Neutral macros that work on all platforms */
+
+#define STORE32L(x, y)                                                                     \
+     { (y)[3] = (unsigned char)(((x)>>24)&255); (y)[2] = (unsigned char)(((x)>>16)&255);   \
+       (y)[1] = (unsigned char)(((x)>>8)&255); (y)[0] = (unsigned char)((x)&255); }
+
+#define LOAD32L(x, y)                            \
+     { x = ((unsigned long)((y)[3] & 255)<<24) | \
+           ((unsigned long)((y)[2] & 255)<<16) | \
+           ((unsigned long)((y)[1] & 255)<<8)  | \
+           ((unsigned long)((y)[0] & 255)); }
+
+#define STORE64L(x, y)                                                                     \
+     { (y)[7] = (unsigned char)(((x)>>56)&255); (y)[6] = (unsigned char)(((x)>>48)&255);   \
+       (y)[5] = (unsigned char)(((x)>>40)&255); (y)[4] = (unsigned char)(((x)>>32)&255);   \
+       (y)[3] = (unsigned char)(((x)>>24)&255); (y)[2] = (unsigned char)(((x)>>16)&255);   \
+       (y)[1] = (unsigned char)(((x)>>8)&255); (y)[0] = (unsigned char)((x)&255); }
+
+#ifndef MIN
+   #define MIN(x, y) ( ((x)<(y))?(x):(y) )
+#endif
+
+
+/* MD5 macros */
+
+#define F(x,y,z)  (z ^ (x & (y ^ z)))
+#define G(x,y,z)  (y ^ (z & (y ^ x)))
+#define H(x,y,z)  (x^y^z)
+#define I(x,y,z)  (y^(x|(~z)))
+
+#define FF(a,b,c,d,M,s,t) \
+    a = (a + F(b,c,d) + M + t); a = ROLc(a, s) + b;
+
+#define GG(a,b,c,d,M,s,t) \
+    a = (a + G(b,c,d) + M + t); a = ROLc(a, s) + b;
+
+#define HH(a,b,c,d,M,s,t) \
+    a = (a + H(b,c,d) + M + t); a = ROLc(a, s) + b;
+
+#define II(a,b,c,d,M,s,t) \
+    a = (a + I(b,c,d) + M + t); a = ROLc(a, s) + b;
+
+
+static void md5_compress(struct md5_state *md5, unsigned char *buf)
+{
+    MD5_INT32 i, W[16], a, b, c, d;
+
+    assert(md5 != NULL);
+    assert(buf != NULL);
+
+    /* copy the state into 512-bits into W[0..15] */
+    for (i = 0; i < 16; i++) {
+        LOAD32L(W[i], buf + (4*i));
+    }
+ 
+    /* copy state */
+    a = md5->state[0];
+    b = md5->state[1];
+    c = md5->state[2];
+    d = md5->state[3];
+
+    FF(a,b,c,d,W[0],7,0xd76aa478UL)
+    FF(d,a,b,c,W[1],12,0xe8c7b756UL)
+    FF(c,d,a,b,W[2],17,0x242070dbUL)
+    FF(b,c,d,a,W[3],22,0xc1bdceeeUL)
+    FF(a,b,c,d,W[4],7,0xf57c0fafUL)
+    FF(d,a,b,c,W[5],12,0x4787c62aUL)
+    FF(c,d,a,b,W[6],17,0xa8304613UL)
+    FF(b,c,d,a,W[7],22,0xfd469501UL)
+    FF(a,b,c,d,W[8],7,0x698098d8UL)
+    FF(d,a,b,c,W[9],12,0x8b44f7afUL)
+    FF(c,d,a,b,W[10],17,0xffff5bb1UL)
+    FF(b,c,d,a,W[11],22,0x895cd7beUL)
+    FF(a,b,c,d,W[12],7,0x6b901122UL)
+    FF(d,a,b,c,W[13],12,0xfd987193UL)
+    FF(c,d,a,b,W[14],17,0xa679438eUL)
+    FF(b,c,d,a,W[15],22,0x49b40821UL)
+    GG(a,b,c,d,W[1],5,0xf61e2562UL)
+    GG(d,a,b,c,W[6],9,0xc040b340UL)
+    GG(c,d,a,b,W[11],14,0x265e5a51UL)
+    GG(b,c,d,a,W[0],20,0xe9b6c7aaUL)
+    GG(a,b,c,d,W[5],5,0xd62f105dUL)
+    GG(d,a,b,c,W[10],9,0x02441453UL)
+    GG(c,d,a,b,W[15],14,0xd8a1e681UL)
+    GG(b,c,d,a,W[4],20,0xe7d3fbc8UL)
+    GG(a,b,c,d,W[9],5,0x21e1cde6UL)
+    GG(d,a,b,c,W[14],9,0xc33707d6UL)
+    GG(c,d,a,b,W[3],14,0xf4d50d87UL)
+    GG(b,c,d,a,W[8],20,0x455a14edUL)
+    GG(a,b,c,d,W[13],5,0xa9e3e905UL)
+    GG(d,a,b,c,W[2],9,0xfcefa3f8UL)
+    GG(c,d,a,b,W[7],14,0x676f02d9UL)
+    GG(b,c,d,a,W[12],20,0x8d2a4c8aUL)
+    HH(a,b,c,d,W[5],4,0xfffa3942UL)
+    HH(d,a,b,c,W[8],11,0x8771f681UL)
+    HH(c,d,a,b,W[11],16,0x6d9d6122UL)
+    HH(b,c,d,a,W[14],23,0xfde5380cUL)
+    HH(a,b,c,d,W[1],4,0xa4beea44UL)
+    HH(d,a,b,c,W[4],11,0x4bdecfa9UL)
+    HH(c,d,a,b,W[7],16,0xf6bb4b60UL)
+    HH(b,c,d,a,W[10],23,0xbebfbc70UL)
+    HH(a,b,c,d,W[13],4,0x289b7ec6UL)
+    HH(d,a,b,c,W[0],11,0xeaa127faUL)
+    HH(c,d,a,b,W[3],16,0xd4ef3085UL)
+    HH(b,c,d,a,W[6],23,0x04881d05UL)
+    HH(a,b,c,d,W[9],4,0xd9d4d039UL)
+    HH(d,a,b,c,W[12],11,0xe6db99e5UL)
+    HH(c,d,a,b,W[15],16,0x1fa27cf8UL)
+    HH(b,c,d,a,W[2],23,0xc4ac5665UL)
+    II(a,b,c,d,W[0],6,0xf4292244UL)
+    II(d,a,b,c,W[7],10,0x432aff97UL)
+    II(c,d,a,b,W[14],15,0xab9423a7UL)
+    II(b,c,d,a,W[5],21,0xfc93a039UL)
+    II(a,b,c,d,W[12],6,0x655b59c3UL)
+    II(d,a,b,c,W[3],10,0x8f0ccc92UL)
+    II(c,d,a,b,W[10],15,0xffeff47dUL)
+    II(b,c,d,a,W[1],21,0x85845dd1UL)
+    II(a,b,c,d,W[8],6,0x6fa87e4fUL)
+    II(d,a,b,c,W[15],10,0xfe2ce6e0UL)
+    II(c,d,a,b,W[6],15,0xa3014314UL)
+    II(b,c,d,a,W[13],21,0x4e0811a1UL)
+    II(a,b,c,d,W[4],6,0xf7537e82UL)
+    II(d,a,b,c,W[11],10,0xbd3af235UL)
+    II(c,d,a,b,W[2],15,0x2ad7d2bbUL)
+    II(b,c,d,a,W[9],21,0xeb86d391UL)
+
+    md5->state[0] = md5->state[0] + a;
+    md5->state[1] = md5->state[1] + b;
+    md5->state[2] = md5->state[2] + c;
+    md5->state[3] = md5->state[3] + d;
+}
+
+
+/**
+   Initialize the hash state
+   @param sha1   The hash state you wish to initialize
+*/
+void md5_init(struct md5_state *md5)
+{
+    assert(md5 != NULL);
+    md5->state[0] = 0x67452301UL;
+    md5->state[1] = 0xefcdab89UL;
+    md5->state[2] = 0x98badcfeUL;
+    md5->state[3] = 0x10325476UL;
+    md5->curlen = 0;
+    md5->length = 0;
+}
+
+/**
+   Process a block of memory though the hash
+   @param sha1   The hash state
+   @param in     The data to hash
+   @param inlen  The length of the data (octets)
+*/
+void md5_process(struct md5_state *md5,
+                const unsigned char *in, unsigned long inlen)
+{
+    unsigned long n;
+
+    assert(md5 != NULL);
+    assert(in != NULL);
+    assert(md5->curlen <= sizeof(md5->buf));
+
+    while (inlen > 0) {
+        if (md5->curlen == 0 && inlen >= MD5_BLOCKSIZE) {
+           md5_compress(md5, (unsigned char *)in);
+           md5->length    += MD5_BLOCKSIZE * 8;
+           in             += MD5_BLOCKSIZE;
+           inlen          -= MD5_BLOCKSIZE;
+        } else {
+           n = MIN(inlen, (MD5_BLOCKSIZE - md5->curlen));
+           memcpy(md5->buf + md5->curlen, in, (size_t)n);
+           md5->curlen    += n;
+           in             += n;
+           inlen          -= n;
+           if (md5->curlen == MD5_BLOCKSIZE) {
+              md5_compress(md5, md5->buf);
+              md5->length += 8*MD5_BLOCKSIZE;
+              md5->curlen = 0;
+           }
+       }
+    }
+}
+
+/**
+   Terminate the hash to get the digest
+   @param sha1  The hash state
+   @param out [out] The destination of the hash (16 bytes)
+*/
+void md5_done(struct md5_state *md5, unsigned char *out)
+{
+    int i;
+
+    assert(md5 != NULL);
+    assert(out != NULL);
+    assert(md5->curlen < sizeof(md5->buf));
+
+    /* increase the length of the message */
+    md5->length += md5->curlen * 8;
+
+    /* append the '1' bit */
+    md5->buf[md5->curlen++] = (unsigned char)0x80;
+
+    /* if the length is currently above 56 bytes we append zeros
+     * then compress.  Then we can fall back to padding zeros and length
+     * encoding like normal.
+     */
+    if (md5->curlen > 56) {
+        while (md5->curlen < 64) {
+            md5->buf[md5->curlen++] = (unsigned char)0;
+        }
+        md5_compress(md5, md5->buf);
+        md5->curlen = 0;
+    }
+
+    /* pad upto 56 bytes of zeroes */
+    while (md5->curlen < 56) {
+        md5->buf[md5->curlen++] = (unsigned char)0;
+    }
+
+    /* store length */
+    STORE64L(md5->length, md5->buf+56);
+    md5_compress(md5, md5->buf);
+
+    /* copy output */
+    for (i = 0; i < 4; i++) {
+        STORE32L(md5->state[i], out+(4*i));
+    }
+}
+
+/* .Source: /cvs/libtom/libtomcrypt/src/hashes/md5.c,v $ */
+/* .Revision: 1.10 $ */
+/* .Date: 2007/05/12 14:25:28 $ */
+
+/*
+ * End of copied MD5 code.
+ *
+ * ------------------------------------------------------------------------
+ */
+
+static PyTypeObject MD5type;
+
+
+static MD5object *
+newMD5object(void)
+{
+    return (MD5object *)PyObject_New(MD5object, &MD5type);
+}
+
+
+/* Internal methods for a hash object */
+
+static void
+MD5_dealloc(PyObject *ptr)
+{
+    PyObject_Del(ptr);
+}
+
+
+/* External methods for a hash object */
+
+PyDoc_STRVAR(MD5_copy__doc__, "Return a copy of the hash object.");
+
+static PyObject *
+MD5_copy(MD5object *self, PyObject *unused)
+{
+    MD5object *newobj;
+
+    if (Py_Type(self) == &MD5type) {
+        if ( (newobj = newMD5object())==NULL)
+            return NULL;
+    } else {
+        if ( (newobj = newMD5object())==NULL)
+            return NULL;
+    }
+
+    newobj->hash_state = self->hash_state;
+    return (PyObject *)newobj;
+}
+
+PyDoc_STRVAR(MD5_digest__doc__,
+"Return the digest value as a string of binary data.");
+
+static PyObject *
+MD5_digest(MD5object *self, PyObject *unused)
+{
+    unsigned char digest[MD5_DIGESTSIZE];
+    struct md5_state temp;
+
+    temp = self->hash_state;
+    md5_done(&temp, digest);
+    return PyBytes_FromStringAndSize((const char *)digest, MD5_DIGESTSIZE);
+}
+
+PyDoc_STRVAR(MD5_hexdigest__doc__,
+"Return the digest value as a string of hexadecimal digits.");
+
+static PyObject *
+MD5_hexdigest(MD5object *self, PyObject *unused)
+{
+    unsigned char digest[MD5_DIGESTSIZE];
+    struct md5_state temp;
+    PyObject *retval;
+    Py_UNICODE *hex_digest;
+    int i, j;
+
+    /* Get the raw (binary) digest value */
+    temp = self->hash_state;
+    md5_done(&temp, digest);
+
+    /* Create a new string */
+    retval = PyUnicode_FromStringAndSize(NULL, MD5_DIGESTSIZE * 2);
+    if (!retval)
+	    return NULL;
+    hex_digest = PyUnicode_AS_UNICODE(retval);
+    if (!hex_digest) {
+	    Py_DECREF(retval);
+	    return NULL;
+    }
+
+    /* Make hex version of the digest */
+    for(i=j=0; i<MD5_DIGESTSIZE; i++) {
+        char c;
+        c = (digest[i] >> 4) & 0xf;
+	c = (c>9) ? c+'a'-10 : c + '0';
+        hex_digest[j++] = c;
+        c = (digest[i] & 0xf);
+	c = (c>9) ? c+'a'-10 : c + '0';
+        hex_digest[j++] = c;
+    }
+    return retval;
+}
+
+PyDoc_STRVAR(MD5_update__doc__,
+"Update this hash object's state with the provided string.");
+
+static PyObject *
+MD5_update(MD5object *self, PyObject *args)
+{
+    unsigned char *cp;
+    int len;
+
+    if (!PyArg_ParseTuple(args, "s#:update", &cp, &len))
+        return NULL;
+
+    md5_process(&self->hash_state, cp, len);
+
+    Py_INCREF(Py_None);
+    return Py_None;
+}
+
+static PyMethodDef MD5_methods[] = {
+    {"copy",	  (PyCFunction)MD5_copy,      METH_NOARGS,  MD5_copy__doc__},
+    {"digest",	  (PyCFunction)MD5_digest,    METH_NOARGS,  MD5_digest__doc__},
+    {"hexdigest", (PyCFunction)MD5_hexdigest, METH_NOARGS,  MD5_hexdigest__doc__},
+    {"update",	  (PyCFunction)MD5_update,    METH_VARARGS, MD5_update__doc__},
+    {NULL,	  NULL}		/* sentinel */
+};
+
+static PyObject *
+MD5_get_block_size(PyObject *self, void *closure)
+{
+    return PyInt_FromLong(MD5_BLOCKSIZE);
+}
+
+static PyObject *
+MD5_get_name(PyObject *self, void *closure)
+{
+    return PyUnicode_FromStringAndSize("MD5", 3);
+}
+
+static PyObject *
+md5_get_digest_size(PyObject *self, void *closure)
+{
+    return PyInt_FromLong(MD5_DIGESTSIZE);
+}
+
+
+static PyGetSetDef MD5_getseters[] = {
+    {"block_size",
+     (getter)MD5_get_block_size, NULL,
+     NULL,
+     NULL},
+    {"name",
+     (getter)MD5_get_name, NULL,
+     NULL,
+     NULL},
+    {"digest_size",
+     (getter)md5_get_digest_size, NULL,
+     NULL,
+     NULL},
+    {NULL}  /* Sentinel */
+};
+
+static PyTypeObject MD5type = {
+    PyVarObject_HEAD_INIT(NULL, 0)
+    "_md5.md5",	        /*tp_name*/
+    sizeof(MD5object),	/*tp_size*/
+    0,			/*tp_itemsize*/
+    /* methods */
+    MD5_dealloc,	/*tp_dealloc*/
+    0,			/*tp_print*/
+    0,          	/*tp_getattr*/
+    0,                  /*tp_setattr*/
+    0,                  /*tp_compare*/
+    0,                  /*tp_repr*/
+    0,                  /*tp_as_number*/
+    0,                  /*tp_as_sequence*/
+    0,                  /*tp_as_mapping*/
+    0,                  /*tp_hash*/
+    0,                  /*tp_call*/
+    0,                  /*tp_str*/
+    0,                  /*tp_getattro*/
+    0,                  /*tp_setattro*/
+    0,                  /*tp_as_buffer*/
+    Py_TPFLAGS_DEFAULT, /*tp_flags*/
+    0,                  /*tp_doc*/
+    0,                  /*tp_traverse*/
+    0,			/*tp_clear*/
+    0,			/*tp_richcompare*/
+    0,			/*tp_weaklistoffset*/
+    0,			/*tp_iter*/
+    0,			/*tp_iternext*/
+    MD5_methods,	/* tp_methods */
+    NULL,	        /* tp_members */
+    MD5_getseters,      /* tp_getset */
+};
+
+
+/* The single module-level function: new() */
+
+PyDoc_STRVAR(MD5_new__doc__,
+"Return a new MD5 hash object; optionally initialized with a string.");
+
+static PyObject *
+MD5_new(PyObject *self, PyObject *args, PyObject *kwdict)
+{
+    static char *kwlist[] = {"string", NULL};
+    MD5object *new;
+    unsigned char *cp = NULL;
+    int len;
+
+    if (!PyArg_ParseTupleAndKeywords(args, kwdict, "|s#:new", kwlist,
+                                     &cp, &len)) {
+        return NULL;
+    }
+
+    if ((new = newMD5object()) == NULL)
+        return NULL;
+
+    md5_init(&new->hash_state);
+
+    if (PyErr_Occurred()) {
+        Py_DECREF(new);
+        return NULL;
+    }
+    if (cp)
+        md5_process(&new->hash_state, cp, len);
+
+    return (PyObject *)new;
+}
+
+
+/* List of functions exported by this module */
+
+static struct PyMethodDef MD5_functions[] = {
+    {"md5", (PyCFunction)MD5_new, METH_VARARGS|METH_KEYWORDS, MD5_new__doc__},
+    {NULL,	NULL}		 /* Sentinel */
+};
+
+
+/* Initialize this module. */
+
+#define insint(n,v) { PyModule_AddIntConstant(m,n,v); }
+
+PyMODINIT_FUNC
+init_md5(void)
+{
+    PyObject *m;
+
+    Py_Type(&MD5type) = &PyType_Type;
+    if (PyType_Ready(&MD5type) < 0)
+        return;
+    m = Py_InitModule("_md5", MD5_functions);
+    if (m == NULL)
+	return;
+}